Hmm, do you need help with how they fit together, or some suggestions on the method to use to attach? I'm not too clear on how they fit. If they don't tell you what to do with the live stitches, maybe you could just bind them off and fake graft them to the fronts.
Is this a free pattern you can link to online? It might help to see the written directions.
"I will remember that no one has ever been killed or maimed by being adventurous with knitting, no matter how pointy the needles." The Yarn Harlot